private final ConcurrentMap<BuilderProblem.Severity, LongAdder> counters;
        private final ConcurrentMap<BuilderProblem.Severity, List<P>> problems;
        private final Predicate<? super P> filter;

        private static final List<BuilderProblem.Severity> REVERSED_ORDER = Arrays.stream(
                        BuilderProblem.Severity.values())
                .sorted(Comparator.reverseOrder())

 * or a simple string message. In addition, a problem carries a hint about its source, e.g. the POM file that exhibits
 * the problem.
 *
 */
public interface ModelProblem extends BuilderProblem {

    /**
     * Enumeration of model versions that can be validated.
     * These versions correspond to different levels of validation that can be applied
     * during model building, based on the POM schema version.